Apparatus for cooling material adversely affected by heat of extrusion



1959 E. N. MEAKIN APPARATUS FOR COOLING MATERIAL ADVERSELY AFFECTED BY HEAT OF EXTRUSION Filed Feb. 3, 1956 m5 W N R A G D E HIS ATTORNEYS United States Patent-*9 hoe g Patented Jan. 27, 1959 The extrusion chamber. is enclosed in a shroud 17 which terminates at its lower end .in a hopper. discharge -19....1

for receiving and guidingthe .pelletsfrom thev machine.

Material to be extruded is fed into the extrusion cham-.

her from a mixer 21 which is supported at .the upper end... of the mill, and supplies .the extrusion chamber through ArrARA'rUs'FoRwooLmG ADVERSELY 'AEFECTED-BY..HEAT.. or v EXTRUsroN flLNcMeakim Hillsboroughu-Calif. Application February 3, 19.56, S.erial No. 563,294 1 5 Claims. (21;- 1s -12) My' invention relates.,to..the..extrusiontof material adversely .affectedby heat .of; extrusion, either physically or. chemically, and more,.particularly. relates .-to. apparatus.

.(1TI l iP QYiQQ QYd. tindi t lipl'oyedmeans for adding a ref s'q' antto. material tb h 'r xtmde a chute 23 runningv from theiront endof .themixing chamber and into the feed opening. in the: cover of the...

extrusion chamber.

The material enters the back-end ofthe mixer,.from,.-

I a feeder mounted above and supported by the-mixer,..

and having connection with the mixer at the rear end thereof. Both the feeder and mixer are equipped .with.. feed screws, that in the mixer being adapted to thoroughly. mix the ingredients which enter the mixer to produce a homogeneous mixture thereof. .Such material is continue.

and such heat can adversely affect certain materials under extrusion. The improvement constituting thepresent invention, serves to counteract. such heat by refrigerating the material through the mixture. therewith of a refrigerantin solid form .such as Dry Ice,.which ultimately,

vaporizes and disappears without .leavingany residue, or. Q

otherwise deleteriously affecting thematerialirom whichfi 21, IQ'R t1.iiilpgjdygdgapparatuseapable.-. epelletsare formed. p IDLEQEQJS! rannwith 'materiahto be Such improvement broadly,.involves rthenapparatusj jl extruded? which is the preferredembodimenngmduallyibo fltes .no l d;..i provei apparatus for P e r dembodiment 'Fign 1 e j"1'"'i's"a front',view in elevation; of a pellet] mill embodying the features of the present invention;

5? & a, dev sw i e evati nsf t erel m 0513361111,

Fi 'lregS isa.f1'a'g'mentary view in section 'throughthat pellet milll of any'conventional type, apparatus 3 adapted.

to 'cooperatetherewith to-;the-"-extent;of -adding to the material tbfbQ extrudeda refiigerant "capable of intimately 'mixing withithe material; ito thereby efiiciently refrigerate the same-and thus' condition it for extrusion without being adversely affected by heat which would otherwisesbe generated-:in such materialduring the extrusion thereof z;

The particular pellet miILiIIustratedis of ,the .type incorporatinga .horizontal cylindrical extrusion chamber 5 'definedby'a rotatable'cylindrical die; 7I which is spanned at-;-th e front by'a substantiallywonicalcover 9 havinga central feed opening --11'"therein:

Within thechamber, in' a diametrical, horizontal plane, arej uppprtedja pair-of extrusion rollers 13 which. are adjustably positioned with-respect to thedie. Material supplied to the extrusion chamber is extruded through the die by these rollers as the die rotates. Extruded material emerging from the discharge side of the die is periodically scraped by stationary knives 15 to form pellets.

to. material.

t. Pparatns'adapted. ry Icqorthelikec will .b fbrought out.

h t e; cc pa y.

provenieritcbnstittiting'fthe essence of1the present inven-' a block 29fof the refrigerantinits.solid; state and;

ee s..- the cornminuted refrigerating. materialstonthe .material; td.

be extruded,- ,and. preferably. prion p to. .the entrance: got;

powered refrigerating equipment, proving not. only 'costly'jj.

in the initial installation thereof, but .alsoexp'ensive in its operation and. upkeep.

In the specific embodiment .of-the, inventionasiiilusal trated in the drawings, .a support in the form of a cradle'... 31 terminating at one endina shrouded hopper 33' mount.

7 ed over an opening..34 in the uppensurface of theifee'de'ru to one side of the materialhopper, is adaptedto receive. a block of refrigerant such as Dry Ice.. y In the shroud portion, of .the.hopper.33,;are. rotatably supporteda pair..of comminuting rolls-37 and 39, oneabovetheothertandgeared to eachrother. Eachroll' is provided with .a plurality of scraper-elements such .aspegs 41 extending from the surface thereof. These rolls, are preferably rotatable toward. each-.other, viewed in the drawings, by means of a suitable-drive chain 43 connecting a drive motor to a sprocket-.47 at one;=

end of one of the rolls -and;.externally of .llheiCOIltZlDEl'.

Means is provided for urging a block of the refrigerant'v against. these,..rolls, whereby-' the rolls in picking away:at-='- the exposed end of the blocs of refrigerant, will serve to comminute the same and cause the small particles thus removed, to drop and be guided into the feeder to move I with the extrudable material to the mixer. In the mixer,

the refrigerating material will become intimately mixed with the material to be extruded and cause the same to become thoroughly refrigerated.

The means for continually urging the block of refrigerating material against the comminuting rolls preferably takes the form of a feed screw 49 disposed longitudinally of the cradle and partially submerged in the floor thereof. This feed screw is connected externally of the container to a sprocket or pulley 51 which is driven from a motor 53 by means of a connecting sprocket chain or belt 55.

The block refrigerant being much colder than the drive screw, will melt down over the exposed portion of the screw to form a screw drive connection therewith, whereby rotation of the screw will force the block of refrigerant in the direction of the comminuting rolls.

To permit of positive and accurate control of the forward movement of the refrigerant, the supporting cradle is preferably mounted in a tilted position with the roll end at a slightly higher elevation than the opposite end. Such manner of mounting, completely eliminates any probability of agrav-itational component of force urging the block in the direction of the rolls, as the movement of the block would then be somewhat difficult to control accurately. Thus such forward movement becomes exclusively the function of the screw drive. v

In connection with the problem of refrigerating the material to be extruded, it is desirable to adjust the rate of refrigeration to both the particular material-passing through the machine, and the rate at which suchmaterial is supplied. Such adjustability is made possible by utiliz-- ing as the screw drive motor, one capableof having its speed adjusted, whereby the rate of movement of the block of refrigerant may be accurately controlled, 'and thereby accurately adjusted to the requirements. of the particular material to be extruded.

It will be'apparent from the foregoing description'jof" my invention in its preferred form, that the same fulfills all the objects attributed thereto, and while I have illustrated and described the invention in its preferred form and in considerable detail, it is apparent that the same is subject to alteration and modification without departing from the underlying principles involved. I accordingly do not desire to be limited in my protection to the specific details so illustrated and described except as may be necessitated by the appended claims.

I claim:

1. In combination with a machine having an' extrusion chamber means for feeding material to said extrusion chamber for extrusion, means for adding a refrigerant to said material prior to extrusion, said means com prising a support for a refrigerant in a solid tate, and

means for comminuting such refrigerant, said means including at least one roll mounted adjacent an end of said support, having a plurality of pegs extending from the surface thereof, means for driving said roll and means for urging a block of such refrigerant toward said roll,

said last means including a drive screw disposed longitudinally of saidsupport and being at least partially exposed thereby to permit such block of refrigerant when positioned on the drive screw to settle down thereon and to effect a screw drive engagement therewith, and means for rotating Said drive screw at a speed which is adjustable to the requirements of the particular material being extruded.

2. In combination with a machine having an extrusion chamber, and means for continuously feeding material to said extrusion chamber for extrusion, means for adding a refrigerant to said material prior to extrusion, said means comprising a support for a refrigerant in a solid state, means for comminuting such refrigerant, said said means being adjustable to .alter the rotational speed of said drive screw, and means for guiding said comminuted refrigerant to said material for'mixing therewith prior to the extrusion thereof. j

3. In combination with a machine having an extrusion chamber, and means for continuously feeding material to said extrusion chamber for extrusion, means for adding a refrigerant to said material prior to extrusion, said means comprising a support for a refrigerant in a solid state, said support being tilted, means for comminuting such refrigerant, saidmeans including a panof rolls mounted adjacent the higherjend of said support, each of said rolls havinga plurality of pegs extending from the surface thereof, means' 'for driving said rolls in opposite directions, and means for-continually urging a block ofsuch-refri gerant upwardlytoward. said rolls,

said means including a 'drive' screw disposed longitudinally of said 'supportand 'beingat' least partially exposed therebyto permit the bloclg of refrigerant tosettle down thereon-'andfto "effect "a rew'jdriv'e: engagement therei i otatingsaid drivejscrew, said means 'the i otatio'nal speed; of said guiding: said comminuted frednve screw,

frig erant :6 ''said inaterial formixing therewith'prior to g the extrustionthereof,

4; Apparatus ar; 'cjoinn' iiiiiting ifmaterialf such as Dry Ice in 'solid' state, comprisin g' of said support, said'roll'having 'scrapermeanson the surface thereof, and ,nieansror positively and controllably urging suchibloc lcof material-toward said roll, said means including a vdrive screw disposed longitudinally of and being at least partially exposed relative to said support thereby to be engaged byvsuch block and to effect a screw engagement'therewith,"and means for rotating said drive screw.

5. Apparatus for comminuting material such as Dry Ice in solid state, comprising a support for a block of such material, a pair of rolls mounted adjacent an end of said support, said rolls each having scraper means on the surface thereof, means for rotating said rolls toward each other, and means for urging such block of material toward said rolls, said means including a drive screw disposed longitudinally of and being at least partially exposed relative to said support thereby to be engaged by such block and to effect a screw drive engage mcnt therewith, and means for rotating said drive screw at a speed which is adjustable to a desired refrigerating effect.

References Cited inv the fileof this patent UNITED STATES PATENTS supportifona block of such material, at least qnemn; ounted adjacent an end 

